Identification of linear fractional order systems using the relay feedback approach

The relay feedback approach has been used to identify integer order models. Fractional order systems are usually identified by many other approaches. Yet, using the relay feedback to identify a fractional order system has not been reported. This paper investigates this interesting and useful topic by means of extending the relay feedback identification method from integer order systems to a class of linear fractional order systems. Equations are derived for model parameter calculation. Simulation and experiments are presented to verify the feasibility and effectiveness of the proposed approach.